TABLE 4.

INCIDENCE OF QFT REVERSIONS AMONG HEALTH CARE WORKERS WITH EITHER QUANTIFERON-TB GOLD IN-TUBE ASSAY–POSITIVE/TUBERCULIN SKIN TEST–POSITIVE RESULTS, OR QUANTIFERON-TB GOLD IN-TUBE ASSAY–POSITIVE/TUBERCULIN SKIN TEST–NEGATIVE RESULTS AT BASELINE^*

Baseline IFN-γ Response, IU/ml	No. Retested after 18 Mo	No. That Received INH after Baseline Survey (%)	Total Reversions	Incidence of Reversions (%)	p Value for Trend in Reversion Rates across IFN-γ Categories
0.35–0.69	11	1 (9)	6	6/11 (55)	< 0.01
0.7–1.0	2	0 (0)	1	1/2 (50)
1.1–5.0	9	3 (33)	1	1/9 (11)
> 5.0	16	9 (56)	1	1/16 (6)
Total	38	13 (34)	9	9/38 (24)

Definition of abbreviations: TST = tuberculin skin test; QFT = QuantiFERON-TB Gold In-Tube assay; INH = isoniazid.

^*n = 38.